Best Free Developer Tools
Free developer utilities: formatters, encoders, hashers, generators and converters — fast and private.
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AI Tool Finder
Describe what you need and AI finds the right tool instantly.
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Base64 Encode/Decode
Encode or decode Base64 strings.
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URL Encoder/Decoder
Encode and decode URL components.
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JSON Formatter
Beautify and validate JSON instantly.
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Regex Tester
Live JavaScript regex tester with match highlighting and flags.
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UUID v4 Generator (Bulk)
Generate any number of cryptographically random RFC 4122 v4 UUIDs.
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API Tester
In-browser REST client: send GET/POST/PUT/PATCH/DELETE with custom headers and body.
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JSON Validator
Validate any JSON string and surface parse errors with line context.
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JSON Compare
Diff two JSON documents and see added, removed and changed keys.
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JSON Path Tester
Resolve a JSONPath expression against any JSON document.
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XML Formatter
Pretty-print and indent any XML document.
✔️
XML Validator
Validate XML well-formedness using the browser DOMParser.
📜
YAML Formatter
Reformat and validate YAML with consistent indentation.
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YAML Validator
Check YAML syntax and surface errors instantly.
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HTML Minifier
Strip whitespace and comments from HTML to shrink page size.
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CSS Minifier
Compress CSS by removing whitespace, comments and trailing semicolons.
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JavaScript Minifier
Strip comments and whitespace from JS source for smaller bundles.
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SQL Formatter
Beautify SQL by breaking clauses onto new lines.
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SQL Beautifier
Alias of SQL Formatter — clause-aware SQL prettifier.
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QR Code Generator
Generate scannable QR codes for any URL or text and download as PNG.
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Markdown Previewer
Render Markdown to HTML live with side-by-side preview.
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Cron Expression Builder
Build and describe 5-field cron expressions visually.
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CSV to JSON Converter
Convert CSV with a header row into a JSON array of objects.
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JSON to CSV Converter
Convert a JSON array of objects into a CSV table.
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JSON to XML Converter
Serialize a JSON document into nested XML elements.
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XML to JSON Converter
Parse XML and emit a JSON structure of the document tree.
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Code Diff Checker
Line-by-line diff between two code snippets with +/- markers.
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MIME Type Finder
Look up the MIME content-type for any file extension.
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User-Agent Parser
Parse a User-Agent string into browser, OS and device class.
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Source Code Beautifier
Auto-indent source code with brace-aware formatting.
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HTTP Header Parser
Parse and align an HTTP header block for easy inspection.
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Base64 Encoder
Encode text to Base64 with UTF-8 support.
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Base64 Decoder
Decode Base64 strings back to UTF-8 text.
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URL Decoder
Decode percent-encoded URL components into readable text.
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API Response Viewer
Send REST requests and inspect the response — alias of API Tester.
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QR Code Reader
Decode any QR code from an image — see exactly what it contains before you trust it.